<template>
    <div class="area">
        <el-scrollbar>
            <el-tree
            :data="data"
            show-checkbox
            node-key="id"
            ref="tree"
            highlight-current
            :default-expanded-keys="[1, 4]"
            :default-checked-keys="[]"
            :props="defaultProps">
            </el-tree>
        </el-scrollbar>
        <!-- <div class="buttons">
            <el-button @click="resetChecked">清空</el-button>
        </div> -->
    </div>
</template>
<script>
export default {
    data() {
      return {
        data: [{
          id: 1,
          label: '一级 1',
          children: [{
            id: 4,
            label: '二级 1-1',
            children: [{
              id: 9,
              label: '三级 1-1-1'
            }, {
              id: 10,
              label: '三级 1-1-2'
            }]
          }]
        }, {
          id: 2,
          label: '一级 2',
          children: [{
            id: 5,
            label: '二级 2-1'
          }, {
            id: 6,
            label: '二级 2-2'
          }]
        }, {
          id: 3,
          label: '一级 3',
          children: [{
            id: 7,
            label: '二级 3-1'
          }, {
            id: 8,
            label: '二级 3-2'
          }]
        }],
        defaultProps: {
          children: 'children',
          label: 'label'
        }
      };
    },
    
    methods: {
      resetChecked() {
        this.$refs.tree.setCheckedKeys([]);
      }
    },
};
</script>
<style lang="scss" scoped>
    .area{
        border: 1px solid #d1d1d1;height: 100%;overflow-x: hidden; margin-right: 20px;
    }
</style>